Two weeks after ending his presidential campaign and a bitter rivalry with Republican frontrunner Mitt Romney, Rick Santorum reluctantly admitted he would support the former Massachusetts governor if he won the nomination on CNN Tuesday night -- but refused to call it an endorsement.

Santorum -- who once said we might as well re-elect President Barack Obama if Romney becomes the nominee and continually lambasted him for being a weak candidate -- tried to keep the focus on Obama's failures when CNN's Piers Morgan grilled him about the presumed GOP general election candidate. Morgan tweeted during the taping of the show that Santorum admitted an endorsement during the commercial break before talking about it on air.

I believe [Romney's] the better - obviously I believed I was the better choice. But I'm not in the race anymore, Santorum said of Romney after he swept five Northeast primaries Tuesday night.

He is the person that is going to go up against Barack Obama. It's pretty clear. We need to win this race.

Also smiling, Santorum said: OK. Could be. Who knows? He's working the delegates really hard, I can tell you that.

The British journalist reached his own conclusion about the conversation. I may be naïve to the American political system, but when somebody says yes, I think he's the right guy for the job, it sounds like an endorsement, he said.